Patents by Inventor Michael Loehning

Michael Loehning has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11901927
    Abstract: Dynamic range of radio frequency transmitters and receivers may be improved via a multiple-channel phasor configuration in which channels are phased in a manner that distributes the local oscillator phases over ?/2 radians. A multiple-channel phasing receiver may include a power splitter to split an input signal into multiple signals, and may further include multiple single-channel receivers providing intermediate signals. Each single-channel receiver may have an input that receives a respective signal of the multiple signals, and may further have an output to provide a respective intermediate signal as a function of the respective input signal, a total gain applied to the respective input signal, a signal frequency of the local oscillator signal, and a respective phase of the local oscillator signal. The multiple-channel receiver may include a digital signal processor that combines the plurality of intermediate signals into a single output signal.
    Type: Grant
    Filed: April 5, 2022
    Date of Patent: February 13, 2024
    Assignee: National Instruments Corporation
    Inventors: Nikhil Ashok Deshmukh, Michael Loehning
  • Publication number: 20230268947
    Abstract: Dynamic range of radio frequency transmitters and receivers may be improved via a multiple-channel phasor configuration in which channels are phased in a manner that distributes the local oscillator phases over ?/2 radians. A multiple-channel phasing receiver may include a power splitter to split an input signal into multiple signals, and may further include multiple single-channel receivers providing intermediate signals. Each single-channel receiver may have an input that receives a respective signal of the multiple signals, and may further have an output to provide a respective intermediate signal as a function of the respective input signal, a total gain applied to the respective input signal, a signal frequency of the local oscillator signal, and a respective phase of the local oscillator signal. The multiple-channel receiver may include a digital signal processor that combines the plurality of intermediate signals into a single output signal.
    Type: Application
    Filed: April 5, 2022
    Publication date: August 24, 2023
    Inventors: Nikhil Ashok Deshmukh, Michael Loehning
  • Patent number: 10312978
    Abstract: In a wireless transceiver station having M antennas, designate an antenna as a target reference antenna (TRA) and for each antenna m other than the TRA: define N distinct paths from antenna m to TRA through zero or more intermediate reference antennas, N is two or more, each distinct paths has a distinct associated set of one or more antenna pairs; for each antenna pair of the sets, estimate an effective forward and backward channel response by sending calibration pilots forth and back between the antenna pair and calculate a reciprocity coefficient for the antenna pair using the estimated channel responses; for each of the N distinct paths, calculate a reciprocity coefficient estimate using the reciprocity coefficients calculated for the set of antenna pairs associated with the path; and combine the N calculated reciprocity coefficient estimates to produce a final reciprocity coefficient estimate for antenna pair (m, target reference antenna).
    Type: Grant
    Filed: July 16, 2018
    Date of Patent: June 4, 2019
    Assignee: National Instruments Corporation
    Inventors: Jörg Hofrichter, Michael Löhning, Eckhard Ohlmer
  • Patent number: 10257005
    Abstract: An apparatus includes circuitry that processes a subframe as part of a time-domain signal frame structure used for radio frequency communications. The subframe includes a plurality of block symbols each having an associated time-domain guard period and one or more radio frequency (RF) switching guard periods. Each block symbol of the plurality of block symbols is either a common block symbol or a special block symbol. A common block symbol has a common time-domain guard period with all other common block symbols of the subframe. A special block symbol has a time-domain guard period different from the common time-domain guard period. All the special block symbols in the subframe are placed into the one or more RF switching guard periods.
    Type: Grant
    Filed: August 10, 2017
    Date of Patent: April 9, 2019
    Assignee: National Instruments Corporation
    Inventors: Michael Löhning, Achim Nahler, Nikhil Kundargi
  • Patent number: 10218549
    Abstract: A post-equalization phase tracking unit, for each signal block of a received series: computes beginning absolute phase rotation using equalized preceding pilot symbols; subdivides the block into a time sequence of groups of equalized symbols; initializes accumulated phase associated with the first-in-time group with the absolute phase rotation. For each group, the unit: computes a de-rotated version of each symbol using the previous group's accumulated phase used to blindly estimate a residual group phase; assigns the group's accumulated phase with a sum of the group's residual phase and the previous group's accumulated phase; estimates phase drift within the group by using at least the group's accumulated phase to compute a phase compensation signal.
    Type: Grant
    Filed: January 24, 2018
    Date of Patent: February 26, 2019
    Assignee: National Instruments Corporation
    Inventors: Michael Löhning, Eckhard Ohlmer
  • Patent number: 10218548
    Abstract: A pre-equalization phase tracking unit, for each signal block of received series: computes autocorrelation between portion of identical-as-transmitted initial and terminal sequences and computes phase of autocorrelation; estimates start phase of block processing window using autocorrelation phase and start phase of previous signal block in series; estimates phase drift within window by interpolating using estimated start phases of at least the signal block and next signal block in series; and computes phase compensation signal using estimated phase drift. A post-equalization phase tracking unit subdivides the block into time sequence of groups of equalized symbols.
    Type: Grant
    Filed: January 24, 2018
    Date of Patent: February 26, 2019
    Assignee: National Instruments Corporation
    Inventors: Michael Löhning, Eckhard Ohlmer
  • Publication number: 20190028155
    Abstract: In a wireless transceiver station having M antennas, designate an antenna as a target reference antenna (TRA) and for each antenna m other than the TRA: define N distinct paths from antenna m to TRA through zero or more intermediate reference antennas, N is two or more, each distinct paths has a distinct associated set of one or more antenna pairs; for each antenna pair of the sets, estimate an effective forward and backward channel response by sending calibration pilots forth and back between the antenna pair and calculate a reciprocity coefficient for the antenna pair using the estimated channel responses; for each of the N distinct paths, calculate a reciprocity coefficient estimate using the reciprocity coefficients calculated for the set of antenna pairs associated with the path; and combine the N calculated reciprocity coefficient estimates to produce a final reciprocity coefficient estimate for antenna pair (m, target reference antenna).
    Type: Application
    Filed: July 16, 2018
    Publication date: January 24, 2019
    Inventors: Jörg Hofrichter, Michael Löhning, Eckhard Ohlmer
  • Publication number: 20180048506
    Abstract: An apparatus includes circuitry that processes a subframe as part of a time-domain signal frame structure used for radio frequency communications. The subframe includes a plurality of block symbols each having an associated time-domain guard period and one or more radio frequency (RF) switching guard periods. Each block symbol of the plurality of block symbols is either a common block symbol or a special block symbol. A common block symbol has a common time-domain guard period with all other common block symbols of the subframe. A special block symbol has a time-domain guard period different from the common time-domain guard period. All the special block symbols in the subframe are placed into the one or more RF switching guard periods.
    Type: Application
    Filed: August 10, 2017
    Publication date: February 15, 2018
    Inventors: Michael Löhning, Achim Nahler, Nikhil Kundargi